I agree with you, up to the point where they ask the exact same question that's literally just fallen off the front page, as it falls off (sometimes before it falls off).

Novice users generally are the least likely to know to do a search so this is not surprising at all.

In any event, the particular case that prompted the original post was a new poster who posted twice, 2 months ago, loved his X-Pro1, now two months later he posts again - he hates it because it isn't a DSLR and is selling it. Bit odd? I recently sold a camera and I didn't feel the need to tell another DPR forum where I posted semi regularly - why would someone who is even less involved do that?

Why make the original posts? A desire to share their experience presumably. Having made a public statement endorsing a camera, a person might then feel the need to "correct the record" in light of further experience.

why bother? No one would question it.

I find that a strange question. If you were on record expressing an opinion and you no longer held that opinion, wouldn't you want to correct it?

no, not at all, not if I wasn't going to "speak" to those people again. Particularly since 2 posts are nothing in the grand scheme of the DPR forums. It's hardly Hansard.

People express opinions in order to support a point of view. If they change their mind, then their on-record statements are now supporting a point of view that they no longer agree with. It is natural to want to correct that

what's "normal" is to tell the bunch of people you have joined, not the one you have decided to leave...